/*
 * @(#)IntegerAttribute.java
 *
 * Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistribution of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 * 
 *   2. Redistribution in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
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 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed or intended for use in
 * the design, construction, operation or maintenance of any nuclear facility.
 */

package org.wso2.balana.attr;

import java.net.URI;

import org.w3c.dom.Node;

/**
 * Representation of an xs:integer value. This class supports parsing xs:integer
 * values. All objects of this class are immutable and all methods of the class
 * are thread-safe.
 * 
 * @since 1.0
 * @author Marco Barreno
 * @author Steve Hanna
 */
public class IntegerAttribute extends AttributeValue {
	/**
	 * Official name of this type
	 */
	public static final String identifier = "http://www.w3.org/2001/XMLSchema#integer";

	/**
	 * URI version of name for this type
	 * <p>
	 * This field is initialized by a static initializer so that we can catch
	 * any exceptions thrown by URI(String) and transform them into a
	 * RuntimeException, since this should never happen but should be reported
	 * properly if it ever does.
	 */
	private static URI identifierURI;

	/**
	 * RuntimeException that wraps an Exception thrown during the creation of
	 * identifierURI, null if none.
	 */
	private static RuntimeException earlyException;

	/**
	 * Static initializer that initializes the identifierURI class field so that
	 * we can catch any exceptions thrown by URI(String) and transform them into
	 * a RuntimeException. Such exceptions should never happen but should be
	 * reported properly if they ever do.
	 */
	static {
		try {
			identifierURI = new URI(identifier);
		} catch (Exception e) {
			earlyException = new IllegalArgumentException();
			earlyException.initCause(e);
		}
	};

	/**
	 * The actual long value that this object represents.
	 */
	private long value;

	/**
	 * Creates a new <code>IntegerAttribute</code> that represents the long
	 * value supplied.
	 * 
	 * @param value
	 *            the <code>long</code> value to be represented
	 */
	public IntegerAttribute(long value) {
		super(identifierURI);

		// Shouldn't happen, but just in case...
		if (earlyException != null)
			throw earlyException;

		this.value = value;
	}

	/**
	 * Returns a new <code>IntegerAttribute</code> that represents the
	 * xs:integer at a particular DOM node.
	 * 
	 * @param root
	 *            the <code>Node</code> that contains the desired value
	 * @return a new <code>IntegerAttribute</code> representing the appropriate
	 *         value (null if there is a parsing error)
	 * @throws NumberFormatException
	 *             if the string form isn't a number
	 */
	public static IntegerAttribute getInstance(Node root)
			throws NumberFormatException {
		return getInstance(root.getFirstChild().getNodeValue());
	}

	/**
	 * Returns a new <code>IntegerAttribute</code> that represents the
	 * xs:integer value indicated by the string provided.
	 * 
	 * @param value
	 *            a string representing the desired value
	 * @return a new <code>IntegerAttribute</code> representing the appropriate
	 *         value (null if there is a parsing error)
	 * @throws NumberFormatException
	 *             if the string isn't a number
	 */
	public static IntegerAttribute getInstance(String value)
			throws NumberFormatException {
		// Leading '+' is allowed per XML schema and not
		// by Long.parseLong. Strip it, if present.
		if ((value.length() >= 1) && (value.charAt(0) == '+'))
			value = value.substring(1);
		return new IntegerAttribute(Long.parseLong(value));
	}

	/**
	 * Returns the <code>long</code> value represented by this object.
	 * 
	 * @return the <code>long</code> value
	 */
	public long getValue() {
		return value;
	}

	/**
	 * Returns true if the input is an instance of this class and if its value
	 * equals the value contained in this class.
	 * 
	 * @param o
	 *            the object to compare
	 * 
	 * @return true if this object and the input represent the same value
	 */
	public boolean equals(Object o) {
		if (!(o instanceof IntegerAttribute))
			return false;

		IntegerAttribute other = (IntegerAttribute) o;

		return (value == other.value);
	}

	/**
	 * Returns the hashcode value used to index and compare this object with
	 * others of the same type. Typically this is the hashcode of the backing
	 * data object.
	 * 
	 * @return the object's hashcode value
	 */
	public int hashCode() {
		return (int) value;
	}

	/**
     *
     */
	public String encode() {
		return String.valueOf(value);
	}

}
